Subject: Right Angles

Joseph Mizerek
lvl : pre-algebra
I am a student

I was wondering why a 90 degree angle is called a Right angle. I mean why isn't called a left angle.

The term right in right angle comes from the meaning of right as proper, or in accordance to justice or equality. It comes from the way a right angle was originally defined. When two straight lines intersect they form two angles. When these angles are equal then this is a fair or just situation and the angles are "right".

Your question "Why isn't called a left angle?" may lead you to wonder if these two distinct meanings of right is an anomoly of English, but it is not. In most western european languages there is one word that means right as opposed to left, right as proper and also right as a human right.